The overall objective of this research is delineation of antecedent cognitive ability prerequisite to development of early child language. Children between the ages of 8 and 24 months will be observed. The observations will consist of a 40-minute videotape record of mother and child interacting with a standard set of play objects, administration of the Albert Einstein Object Permanence Scale and administration of the Bayley Scales of Infant Development. The child's level of representation will be determined by his performance on the Object Scale and by the level of symbolic play demonstrated in his use of the play objects (Nicolich, 1975; Piaget, 1962). Because of the role of vocal and gestural imitation in bringing about mental representation (Piaget, 1962; Werner and Kaplan, 1963), it is suggested that vocal imitation may have an analogous role in language production (Bloom, Hood, and Lightbown, 1974; Nicolich and Raph, in press) Imitation is considered in a cognitive framework as a process which includes internal organizing activity as a response prior to external reproduction. The child language recorded in each interaction session will be transcribed and the following variables analyzed: (a) the level of representation achieved when certain language milestones, such as the production of multi-word combinations, emerge for each child; (b) the extent of imitation and the basis for selection of words to be imitated; (c) the extent to which the children's use of imitation is consistent across representation levels and across children in the sample; and (d) sex differences, if any, with respect to these variables. The relationship of Bayley Subscale scores to symbolic development and language development will be explored.